Slow leak device



Oct. 18, 1932. L. A. GRIMES 1,883,720

SLOW LEAK DEVICE Filed Aug. 14, 19:50

INVENTOR l es/er' 0. 6770168.

ATTORNEYS Patented Oct. 18,1932

vmammms '2 LESTER A. GRIMES, or MONTCIJAI'R, NEW

coMPANY, me, or NEWARK, new JERSEY, A CORPORATION or NEW anasnx s fi i fnnvmfi Application ma'n'gust' 14; 1 e q.f Serial m; 475319;"

The present invention relates; to a i slow leak or breathing device for usein apparatus of the type which is responsive to'rat'e of change of fluid pressure, such as accelera'tors or exhausters fordry pipesprinkler systems, pneumatic or thermostatic apparatus, or the like. w

Slow leak devices heretofore employed, in-

cluding pinhole orifices or restricted pas- I tional view of'the sages become readily clogged .with. dustjor other foreign matter with consequentrfalse operation of the, apparatus in which they are employed. The device'of the present] invention avoids this disadvantage of the usual leak devices bythe provision. of roughened surfaces in place of the usual pin hole or similar constricted opening, leakage occurring between the surfaces over a considerable area. 4

For a better understanding of the invention reference may be had to the accompanying drawing in which is illustrated a secpreferred embodiment of the invention. I V a P Referring to the drawing, a cylindrical member 1 has a partition 2 across the bore thereof within which is a relatively large passage 3. Cemented or soldered in any suitable manner to one side of the partition 2 is a disk 4 with a central passage 5 therethrough in alinement with the passage 3. A

second disk 6, of a diameter sufficiently smaller than the bore of member 1 to permit ready insertion or removal thereof, and to permit relatively unrestricted flow of fluid about the periphery of the disk, is heldin engagement with the disk 4 by means of an externally threaded member 7 adapted to be P screwed into one end of the cylindricalmember 1. Member 7 is provided witha plurality of passages 8 therethrough and-with a projecting portion Q'aclapted toengage the disk 6 when the parts areassembled. -Wire gauze or other filtering material, indicated at v45 10 and 11, covers the entrance to passages/3 lzePreferably. both fsurfaces offi;disk

may. Assam o s ME sral naa and s i-Member "1 "as, -shown, zis' :over apart of its external surface and-11%;} a headgformed atone endthereofl 1min be understood that the device,",--when in useyis;

. screwed into the wall of iachamber orfof?a pipeifor the purpose of permitting normal equalization through thedev ice' of the-presf- .sures at either side thereof :while preventing such ,2 pressure; 1, equalization during rapid igchanges Sf-the pressure ateither side thereof.

9 1T0 provide a restricted' passage through of an abrasive or grinding material to permit the passages 3 -a-nd 5 thus spreads, radially Qfrom the passage 5 between the roughened, surfaces of disks 4 and" 6 and-then? passes throughgthepassa'ges 8; and filter 11. 5 r

. F ora given area ofsurface "ofdiskfiythe preferred. degree of roughness ofthe'fcon-v tacting surfaces of'disks 4- and6 will depend a around the periphery *ofdisk G'iand 'out .up'onthe use to whichf'the device 'is tobe put;

that is upon theznormaljrate of leakage ide- Siredli I. a

a The greater more. rough or coarse shouldbe'. --thereof,*for agivenleakage 7 Where the slow leak device is in valve accelerating devices for'dry pipe sprinkler systems' to permit. pressure equalization through the leak during'slow' pressure; j changes but to preventfsuch equalizationwhen.

the aimeeibf the disks, a

the surfaces to be p the pressure ateither side ofthe leakldevice changesyat a rapid rate,- the surfaces iof-disks 4fand' Gare preferably roughened to about the 7 1 degree of ground lass: fora diameter. oftdisk purpose a .grinding compositionbfth type 1: dium 'coars'eness is suitable. r

Lara! V roughened to the same degree to insure that the same leakage is obtained irrespective of the manner in which the disk is inserted in the device during assembly. If desired, however, the two surfaces of disk 6 could be 7 1 ground to diii'erent degrees of roughness to permit the same device to be used under conditions requiring different degrees of leakage,

as might occur, for'example, upon a change inthe consistency of the fluid whose leakage is to becontr-olled.

Disks 4 and 6 shouldbe constructed of nonond disk in contact with said firstmentioned disk, said disks being of non-corrosive material and having their contacting surfaces corrosive material to insure permanence of V the roughened surfaces thereof. Glass or Mon'el metaldisks are particularly suitable for usei Forclarity, and to illustrate a practical embodiment of the invention and one -suitable for use in such mechanisms asvalve ace a celerating of exhausting devices, a specific construction 'has'been described and illustrated The invention, however,is concerned.

primarily with the substitution for a pinhole 01 gconstr'icted orifice of contacting rough- V a ened surfaces whereby leakage i occurs over an extended area and the disadvantages inherent with the pin hole construction are eliminated; Moreover the use, of roughened contactingsurfaces in slow leak devices permits'. of a construction which maybe readily disassembled for cleaning, inspection or re- .P ain m:

. From a manufacturing standpoint it is convenient to provide the disk 4 as an element made separately from the device 1 and cemented to partition 2. Inasmuch as disk 4 servesonly to provide a roughened surface for contact with that of disk 6 it need not be removable and could, in fact, be integral with,

or-part of, structure 1;

The following .is claimed: 1. A slow leak device comprising in coinbination a member having apassagethere through, a; pair of elements locatedin said passage, one of said elements having an aper ture therethrough and being so disposed in said passage as to prevent leakage of fiuid therepassed except through said apertureand the other of said elements being vnon-apertured and having dimensions substantially less than that of the cross-section of the pas- ;sage through saidfimember, and means for holding said elements inc-ontact; the surfaces of said elements being roughened'where in contaotwhereby fluid passing through said i aperture may leak between. the contacting roughenedsurfaces of said elements.

r 2.lA-slow leak device comprisingin combination a member having =acylindrica1 passage therethrough and an apertured partition --ac'ross sa1d;passage,ad1sk cemented tosald partition and having an aperture in aline- '''ment with: that of said partition, a second disk, and an aperturedplug adapted 'tobe +screwed into said member-to holdsaid ES8C- 

